RUBBER COMPOSITION FOR TREADS AND PNEUMATIC TIRE
First Claim
1. A pneumatic tire, comprising a tread formed from a rubber composition for treads, the rubber composition comprising:
- a polybutadiene; and
a terpene resin having a glass transition temperature (Tg) of 40°
C. to 90°
C.,the polybutadiene satisfying the following conditions (A), (B), and (C);
(A) a ratio (Tcp/ML1+4, 100°
C.) of 5% by mass toluene solution viscosity (Tcp) to Mooney viscosity (ML1+4, 100°
C.) is 0.9 to 2.3;
(B) a stress relaxation time (T80) is 10.0 to 40.0 seconds, which is a time required for torque to decay by 80%, where 100% represents torque at the end of a ML1+4, 100°
C. measurement; and
(C) a molecular weight distribution (Mw/Mn) is 2.50 to 4.00.
1 Assignment
0 Petitions
Accused Products
Abstract
Provided are a rubber composition for treads which achieves a balanced improvement in fuel economy, abrasion resistance, and wet grip performance while offering good processability, and a pneumatic tire formed from the rubber composition. The present invention relates to a rubber composition for treads containing: a polybutadiene; and a terpene resin having a glass transition temperature (Tg) of 40° C. to 90° C., the polybutadiene satisfying the following conditions (A), (B) and (C): (A) a ratio (Tcp/ML1+4, 100° C.) of 5% by mass toluene solution viscosity (Tcp) to Mooney viscosity (ML1+4, 100° C.) is 0.9 to 2.3; (B) a stress relaxation time (T80) is 10.0 to 40.0 seconds, which is a time required for torque to decay by 80%, where 100% represents torque at the end of a ML1+4, 100° C. measurement; and (C) a molecular weight distribution (Mw/Mn) is 2.50 to 4.00.
-
Citations
3 Claims
-
1. A pneumatic tire, comprising a tread formed from a rubber composition for treads, the rubber composition comprising:
-
a polybutadiene; and a terpene resin having a glass transition temperature (Tg) of 40°
C. to 90°
C.,the polybutadiene satisfying the following conditions (A), (B), and (C);
(A) a ratio (Tcp/ML1+4, 100°
C.) of 5% by mass toluene solution viscosity (Tcp) to Mooney viscosity (ML1+4, 100°
C.) is 0.9 to 2.3;
(B) a stress relaxation time (T80) is 10.0 to 40.0 seconds, which is a time required for torque to decay by 80%, where 100% represents torque at the end of a ML1+4, 100°
C. measurement; and
(C) a molecular weight distribution (Mw/Mn) is 2.50 to 4.00. - View Dependent Claims (2, 3)
-
Specification